1. Field of the Invention
The present invention relates to an optical apparatus having a vibration compensation device equipped with vibration compensation functions and, more particularly, to an optical apparatus having a vibration compensation device which compensates for the effects of hand motion or other vibrations on the optical apparatus and is operable during photographic preparations.
2. Description of the Related Art
Autofocus (AF) devices have been common in conventional camera photographic equipment. The addition of vibration compensation devices to compensate for hand vibration of the camera photographic equipment has been proposed. Vibration compensation devices detect fluctuations in the angle along the optical axis caused by hand vibration or movements, and then compensate the photographic picture plane based on those fluctuations. Examples of such vibration compensation devices are disclosed in Japanese Patent No. JP 2-66535 (an example of a single lens optical system) and Japanese Patent No. JP 2-183217 (an example of image compensation by shifting a portion of a telescopic lens optical system).
In these conventional vibration compensation devices, image compensation due to vibration performed only during exposure is considered sufficient. However, the viewfinder image vibrates during photographic preparations, making observation difficult.
Also, because the AF device operates when the release switch is pressed to a half-depressed position, if the photographic preparations have begun, there is the possibility that the distance measurement would not be accurate if the object to be photographed is vibrating. Additionally, when performing multi-pattern light measurement, if the field is vibrating, the value of the measured light may vary due to fluctuations in the brightness of the partitioned areas.
To solve these types of problems it has been suggested to perform the vibration compensation function prior to exposure. However, by performing the vibration compensation function prior to exposure, the battery life will be shortened. The inventors have discovered the above-noted problems and have developed solutions to these problems.